Short-circuiting device



Oct. 13, 1925- J L. BROWN SHORT CIRCUITING DEVICL') Filed Oct. 15. 19257INVENTOR John LyaH Brown.

WITNESSES: 1

A'TTORNEY Patented Oct. 13, 1925.

UNITED STATES PATENT OFFICE.

JOHN LYALL BROWN, OF VEBONA, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSEELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SHORT-CIRCUITING DEVICE.

Application filed October 15, 1923.

To all whom it may concern:

Be it known that I, JOHN LYALL BROWN, a citizen of the United States,and a resident of Verona, in the county of Allegheny and State ofPennsylvania, hay e invented a new and useful Improvement inShort-Circuiting Devices, of which the following is a specification.

My invention relates to shortcircuiting devices or other speedresponsive devices particularly adapted for electric machines, and ithas particular relation to centrifugally-operated mechanisms foreffecting a repulsion operation of a machine during the starting and aninduction operation during the normal operating period.

My invention has for one of its objects to provide a simple, practicaland relatively inexpensive device of the above character, wherein aplurality of members are simultaneously actuated centrifugally in adirection transverse to the axis of rotation, and concurrently in anaxial direction to operate the short-circuiting means into engagementwith the end of the commutator cylinder.

In the accompanying drawing,

Figure 1 is a front view of the device, in section on the line II ofFig. 2,

Fig. 2 is a view in cross section thereof on the line II--II of Fig. 1,and showing the application thereof to the commutator of an electricmachine,

Fig. 3 is a side viewof the contact memhers,

Fig. 4 is a plan view of one of the contact members, and

Fig. 5 is an enlarged side view of one of the pivotal members upon whichthe centrifugal members operate.

In the practice of my invention, I provide a stud plate 1, preferably inthe form of a flanged disc or head, centered upon the shaft 2 of themachine. The machine is provided with a commutator cylinder 3 which ismounted upon a supporting core or spider 3. The head 1 is secured inspaced relation to the end of the commutator spider 3 by means of aplurality of equidistantly spaced screws 4 upon which are fixedlymounted worm-studs or pivot members 5 having steep-threaded or spirallyribbed body portions 6 thereon, said worm-studs also serving as spacingmeans Serial No. 668,467.

between the stud plate 1 and the supporting spider 3 of the commutatorcylinder 3.

A weighted centrifugal member 7 having a properly threaded eccentricopening 8 and a weighted body or enlarged portion 9, is provided tooperatively engage upon the threaded portion 6 of each stud member 5.

The centrifugal members 7 are maintained under suitable tension by meansof three similar spiral tension springs 10, the weight members 7 beingnormally held in engagement with the commutator shaft 2-by the tensionof said springs 10. One end of each spring is connected to a pin 11located at a certain distance from the operating center of one weightmember and the other end of the spring is connected to a pin 12 locatedat a greater effective distance from the operating center of the nextweight member. Since the springs are connected thus alternately, eachspring tends to move one of its associated weight members to the inposition and the other to the out position, the resultant effect,however, being to hold all members in their in or normal position.

Loosely mounted for lateral movement on the worm-studs 5 and adjacent tothe end of the commutator cylinder, is a follower plate or disc 13having a flanged rim 14 thereabout. The follower plate 13 is normallyheld in spaced relation to the end of the commutator by spiralcompression springs 15 disposed upon the stud members 5. The followerplate 13 is provided, upon its inner face portion adjacent to the rimthereof, with a plurality of yieldable phosphor-bronze short-circuitingcontactors 16 which are designed to have great resiliency and to providea wiping action at the contact points, which is always desirable insecuring good contact, especially when the contacting surfaces becomecorroded, as when the motor is idle for long periods. As shown in Figs.3 and l, the contactors are arc-shaped pieces having their intermediateportions bent out, as at 17, but hav ing cup-shaped central depressions18 to provide two contact points 19 for each contactor. The fiatterminals of the contactors are perforated and riveted to the followerplate as at 21.

In operation, at a predetermined speed of rotation of the armature towhich the device is applied, the centrifugal force on the weightedmembers 7 begins to exceed the net closing moment of the springs. Theweighted members immediatel and rapidly rotate to their outermostpositions agalnst the rim of the stud plate 1, and in so rotating,travel axially also, by reason of the threads of the worm-studs 5 uponwhich they are pivotally mounted. The follower plate 13 is thus causedto move toward the commutator, overcoming the opposition of the smallcom ress'ion springs 15, and bringing the yiel able contactors 16 intofirm engagement with the end of the commutator cylinder, thusshort-circuitin the armature. Upon collapse of the centrifugal moment ofthe weight members 7, resulting from the stoppin of the motor, thesprings restore the mechanism to the starting position.

During the above-described operation, the interlocking of the springs 10with the weight members 7 compels all of said members to operatesimultaneously in spite of the difference in either spring or weightmoments. For example, if one of the three weight members here shownshould have a greater centrifugal moment than the other two, and as aresult, it should start to open inadvance of the others, the action ofthe spring which tends to maintain this memher 7 in a closed positionand at the same time tends to eflect an open position of an adjacentweight member connectedthereto would be unduly stresse' retardi themotion of the first Weight member an decreasin the resultant sprin forcetending to ho d said adjacent wage member closed. Again, the pull of thespring which tends to open the first-mentioned member and at the sametime tends to close the adjacent third member will be decreased. Suchaction will also tend to retard the movement of the first-mentionedmember and to facilitate the operating of the third member.

While I have shown and described a certain embodiment of my invention, Idesire that the disclosed embodiment'shall be regarded as illustrativeonly, and that the a pended claims shall be accorded the broadestconstruction consistent with the prior art.

I claim as m invention:

1. The combination with the commutator cylinder of a d namo-electricmachine, of a member space from and secured to the end thereof by aplurality of spaced threaded pivot members, a c'entrifugal'ly actuatedmember pivotally and threadedly mounted on each ofthe threaded ivotmembers, and a short-circuiting mem r loosely dis osed between saidspaced member and said commutator cylinder, said centrifugally-actuat'edmembers adapted to pivot outwardly and simultaneously therewith toadjust themselves axially on their pivot members and force theshort-cirwiting' mber into engagement with the end of t commutatorcylinder.

2. The combinatimi with the commntltnr cylinder of a dynamo-electricmachine, of a member s aced from, and secured to, the end thereof by aplurality of spaced pivot members, a centrifu ally-actuated membermounted on each 0' the pivot members,

means yieldingly connecting said centrifl ugally-actuated members to oneanother, a short circuitin'g member'ioosel disposed between said spacedmember an said commutator cylinder and yielding means ndr mally holdingthe short-circulting member pivot members, and a cirbnitclosing memer'slidably mounted on said piv'otineitibers, said centrifugally-actnatedmemben adapted to be pivotally actuated outwalfi by centrifugal forceandconcurrentlyth with to adpi'st themselves akially'on said' threadedmembers to move the circuit-clue ing member into engagement with the endof the commutator cylinder.

4. The combination with the commutator cylinder of an electric machine,of a phirality of steep-threaded pivot members fixedly attached theretoin extending from the en thereof, s cc a trifugally-actuated membercorres on threaded to, and mounted on, e'ac of pivot members, springsconnecting said en. trifugally-actuated members to one anothe and acircuit-closing member slidalfl; mounted on said ivot members, saidobntrifu'gally-actu members adapted to be pivotally actuated outwardlyby centrifugal force and concurrently therewith to adjust themselvesaxially on said threaded members to move the circuit-closin memberintoaced mus um -1i0 engagement with the end of the commutaton cylinder.

5. The combination with the commutator cylinder of an electric machine,of a rurality of spirally ribbed pivot members xed'ly extending from theend thereof, a stop member secured to the outer ends thereoi, ;aweighted centrifugally-actuated member having a spirally ribbed openingtherein movably fitted on each of said pivot members, a plurality ofsprings connecting said centrifugally-actuated members to one another,and a short-circuiting member movably mounted on said pivot membersadjacent to the end of the commutator cylinder and adapted to be movedinto engagement with the end of the commutator cylinder by the action ofsaid centrifu al members.

6. The combination wit a commutator cylinder of an electric machine, ofa plurality of spirally ribbed pivot members extending therefrom inspaced relation, a stop member secured to the outer ends thereof, aweighted centrifugally-actuated member having a spirally-ribbed openingtherein movably fitted on each of said ribbed pivot members, a pluralityof springs connecting said centrifugally-actuated members to oneanother, a follower member slidably mounted on said pivot membersadjacent to said commutator cylinder, short-circuiting contacts carriedby said follower member, and spring means for normally holding thecontact carrying follower member out of shortcircuiting engagement withsaid commutator cylinder, said centrifugally-actuated members beingadapted to swing outwardly and simultaneously therewith to move axiallyon said ribbed pivot members to actuate the contact carrying followermember into short-circuiting position.

7. A circuit making and breaking device comprising a substantially flatcontact memher and a relatively movable contactor member, the lattercomprising a supporting member and a resilient Contact member securedthereto at its two ends and having its intermediate portions bent outtowards said substantially flat contact member, said outwardly bentintermediate portions having a cup-shaped central depression to providetwo contact points for engaging said substantially flat contact memberwith a wiping action.

8. The combination with a substantially fiat contact member comprisingthe smooth end surface of the commutator segments of a dynamo-electricmachine, of an axially movable contactor member, the latter comprising asupporting member and a resilient contact member secured thereto at itstwo ends and having its intermediate portions bent out towards saidsubstantially flat contact member, said outwardly bent intermediateportions having a cup-shaped central depression to provide two contactpoints for engaging said substantially flat contact member with a wipingaction.

In testimony whereof, I have hereunto subscribed my name this 9th day ofOctober, 1923.

JOHN LYALL BROWN.

